Re: [dpdk-dev] [PATCH v2 3/5] vhost: do not inline unlikely fragmented buffers code

[Tiwei Bie <tiwei.bie@intel.com>]

On Fri, May 17, 2019 at 05:06:11PM +0200, Maxime Coquelin wrote:
[...]
>  
> +static void
> +copy_vnet_hdr_from_desc(struct virtio_net_hdr *hdr,
> +		struct buf_vector *buf_vec)
> +{
> +	uint64_t len;
> +	uint64_t remain = sizeof(struct virtio_net_hdr);
> +	uint64_t src;
> +	uint64_t dst = (uint64_t)(uintptr_t)&hdr;

typo: s/&hdr/hdr/

> +
> +	/*
> +	 * No luck, the virtio-net header doesn't fit
> +	 * in a contiguous virtual area.
> +	 */
> +	while (remain) {
> +		len = RTE_MIN(remain, buf_vec->buf_len);
> +		src = buf_vec->buf_addr;
> +		rte_memcpy((void *)(uintptr_t)dst,
> +				(void *)(uintptr_t)src, len);
> +
> +		remain -= len;
> +		dst += len;
> +		buf_vec++;
> +	}
> +}
> +
>  static __rte_always_inline int
>  copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
>  		  struct buf_vector *buf_vec, uint16_t nr_vec,
> @@ -1094,28 +1126,7 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
>  
>  	if (virtio_net_with_host_offload(dev)) {
>  		if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
> -			uint64_t len;
> -			uint64_t remain = sizeof(struct virtio_net_hdr);
> -			uint64_t src;
> -			uint64_t dst = (uint64_t)(uintptr_t)&tmp_hdr;
> -			uint16_t hdr_vec_idx = 0;
> -
> -			/*
> -			 * No luck, the virtio-net header doesn't fit
> -			 * in a contiguous virtual area.
> -			 */

It's better to not move above comments.

For the rest,
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>

> -			while (remain) {
> -				len = RTE_MIN(remain,
> -					buf_vec[hdr_vec_idx].buf_len);
> -				src = buf_vec[hdr_vec_idx].buf_addr;
> -				rte_memcpy((void *)(uintptr_t)dst,
> -						   (void *)(uintptr_t)src, len);
> -
> -				remain -= len;
> -				dst += len;
> -				hdr_vec_idx++;
> -			}
> -
> +			copy_vnet_hdr_from_desc(&tmp_hdr, buf_vec);
>  			hdr = &tmp_hdr;
>  		} else {
>  			hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
> -- 
> 2.21.0
>